test(agents): add unit tests for exec output rendering helpers

src/agents/bash-tools.exec-output.test.ts

@@ -0,0 +1,59 @@
+// Tests for exec output rendering helpers.
+import { describe, expect, it } from "vitest";
+import { renderExecOutputText, renderExecUpdateText } from "./bash-tools.exec-output.js";
+
+describe("renderExecOutputText", () => {
+  it("returns placeholder for undefined input", () => {
+    expect(renderExecOutputText(undefined)).toBe("(no output)");
+  });
+
+  it("returns placeholder for empty string", () => {
+    expect(renderExecOutputText("")).toBe("(no output)");
+  });
+
+  it("returns value for non-empty string", () => {
+    expect(renderExecOutputText("hello")).toBe("hello");
+  });
+
+  it("returns value for whitespace-only string", () => {
+    expect(renderExecOutputText("  ")).toBe("  ");
+  });
+
+  it("preserves newlines in output", () => {
+    expect(renderExecOutputText("line1\nline2")).toBe("line1\nline2");
+  });
+});
+
+describe("renderExecUpdateText", () => {
+  it("returns placeholder when no tailText and no warnings", () => {
+    expect(renderExecUpdateText({ warnings: [] })).toBe("(no output)");
+  });
+
+  it("returns tailText when no warnings", () => {
+    expect(renderExecUpdateText({ tailText: "hello", warnings: [] })).toBe("hello");
+  });
+
+  it("returns warnings when no tailText", () => {
+    expect(renderExecUpdateText({ warnings: ["warning1"] })).toBe("warning1\n\n(no output)");
+  });
+
+  it("returns warnings followed by tailText", () => {
+    expect(renderExecUpdateText({ tailText: "hello", warnings: ["warning1"] })).toBe(
+      "warning1\n\nhello",
+    );
+  });
+
+  it("joins multiple warnings with newlines", () => {
+    expect(renderExecUpdateText({ tailText: "hello", warnings: ["warning1", "warning2"] })).toBe(
+      "warning1\nwarning2\n\nhello",
+    );
+  });
+
+  it("handles empty warnings array with tailText", () => {
+    expect(renderExecUpdateText({ tailText: "hello", warnings: [] })).toBe("hello");
+  });
+
+  it("handles undefined tailText with warnings", () => {
+    expect(renderExecUpdateText({ warnings: ["warning1"] })).toBe("warning1\n\n(no output)");
+  });
+});